Window sash balance



Aug. 18, 1936. D. M. LEWIS ET AL 2,051,412

WINDOW SASH BALANCE Filed May 9, 1955.

INV NTOR DONALD .Lzwns' EDGAR L. GARDNER ORNEY Patented Aug. 18, 1936UNITED STATES PATENT OFFICE WINDOW SASH BALANCE Application May 9, 1935,Serial No. 20,670

6 Claims.

This invention relates to counter-balancing devices and moreparticularly to window sash balances.

In one type of sash balance, it has been customary to employ meansincluding a retractile spring mounted at each side of the window frame,for the purpose of supporting the window sash in any position to whichit has been moved. In order to counter-balance different weights ofwindow. sashes, balances utilizing springs of different strengths havebeen provided, but since the range of satisfactory operation of any onespring has been rather limited, it has been necessary to provide arelatively large number of types of balances to accommodate thedifferent weights of window sashes. It has also been found that evenamong sash sections of a given type and size, the thickness, andtherefore, the weight of the glass therein varies within wide limits, sothat frequently two different ranges of springs must be provided toproperly balance the different sashes of a given size. It has beenproposed, in the past, to provide a friction brake for the spring cup,housing the retractile spring of a sash balance, but such an arrangementhas not proved to be satisfactory, since it frequently imposes such ahandicap on the action of the spring, that many times it will not rewindthe sash supporting tape when the sash is elevated, but insteadpermitsthe tape'to loop outside of the sash balance housing, with thepossible result that it may become kinked and broken, therebynecessitating replacement.

In accordance with the main feature of the present invention, novelmeans are provided whereby the spring of a sash balance may becompensated in such a manner thatthe possible range of any given pair ofsash balances is extended and yet the operating tension may be properlyset to afiord the best possible counter-balancing of their sash, therebyinsuring reliable operation.

A further feature of the invention relates to a novel construction andarrangement of parts whereby a simple, compact sash balance can beprovided.

For a clearer understanding-of the invention, reference is made to thedrawing in which Fig. 1 shows a window frame with a pair of windowsashes mounted therein, and a pair of sash balances mounted in the sidesof a window frame to have one end of their spring actuated tapesconnected to the respective sides of one of the sashes; Fig. 2 is aperspective view of a sash balance of the present invention; Fig. 3

is a sectional view therethrough, substantially on the line 33 of Fig. 4looking in the direction of the arrows; Fig. 4 is a sectional. view 5thereof taken 'on the line 4-4 of Fig. 3 likewise looking in thedirection of the arrows; Fig. 5 is a fragmentary view of the hood,showing the arrangement of the adjusting screw therein and Fig. 6' is asectional view taken 10 on the line 6-6 of Fig. 5.

Referring especially to Fig. 1, 5 and 6 design nate respectively, thesides of a window frame having a top portion 1 and the window ledge 8.Two window sash sections generally designated 9 and Ill are slidablymounted in any well-known manner in the window frame, so that they maybe opened or. closed. In order to counter-balance the weight of one ofthe sash sections such as 9, and thereby facilitate its movement andhold it in the position to which it has been adjusted, there is mountedin recesses H at each side of the frame, a sash balance I2 according tothe present invention.

Each sash balance includes a hood I4 prefere ably formed of sheet metal.This hood centrally of its side I5, is provided with an apertured hub l6on which there is rotatably mounted, a circular, stamped-out metal diskl! with an offset annular rim parallel to the principal plane of thedisk and having gear teeth out about its edge. An adjustable screw 20provided intermediate its ends with a worm 2| engaging the gear teeth onthe disk I1 is mounted in the position shown, by means of a supporting 5strip I8 which is struck out of the side l5 of the hood and is wrappedabout the shank of the screw as shown best in Figs. 3, 5, and 6. Itshould be noted that the screw 20 occupies the upper corner of the hood,which has cut-out portions Ma and Nb in which the worm 2| and the head22 of the screw project. While this screw has been illustrated asoccupying the upper corner of the hood, in certain types of sashbalance, it should preferably be mounted in the 7 corresponding lowercorner thereof. The construction of the disk and the mounting of theadjusting screw aiford an especially compact arrangement of parts. Thescrew 20 terminates in a slotted head 22 adjacent an opening 4l'i'n theframe 23, of thesash balance. Within the hood there is also'provided aspring cup 24 to retain the retractile spring 25, which cup at its openside projects into the central offset-portion of the disk H which inturn 55 65 p p tured hub foifmedocentrally thereon to engage the freeend of said sleeve, a retractile spring servesas a closure therefor. Thecup is also provided with a depressed circular shoulder 26 .having anaperture therein, which shoulder serves to center a split sleeve 21having its righthand end (as shown in Fig. 4), staked to, or otherwise,attached to the disk [1, as indicated at'points 28. The inner end of theretractile spring 25 is bent to form a hook which engages the splitportion of the sleeve 21, as shown at 29 (Fig. 3), while the other endof this spring is bent to form a second hook which engages an ear 30struck out from the rim of the spring cup. On the rim of the spring cup,there, is wound a flexible tape l3 provided at one end with a loop 32,which may belattached to a hook 40 (Fig. l), on the edge of; thesashsection 20 flat face plate 34 formed with screw holes 3 5 inventioncomprises a practical, compact sash balance which can easilybeimanuiactured, easily 9. .The other end of the fiexible't'ape l3terminates in a hook engaging an opening at 3 3 l in the rim or sidewall of the spring cup.

The frame 23 of the sash balance having a by which the sash balancemaybe fastened to the side frame offthewindow', is provided with a rightangular extension 36 -which serves as. a closure for'the op'en'side ofthe hood, and. with alsecond right angular extension '31 parallel to thefirst extension 'andfindicated in' dotted lines in"Fig,f 3. Both angularextensions are provided with openings ill?v in 'alinementfto'receive apin 39 which ser'ves to Inaintain'the parts in assembled position. Thefac'e plate near its top is also provided, with an opening 4| throughwhich thefsc rfw 2'0is adjustable and infaddition'is provided with"anepemng 42.1through which an end' portion of the tape l3 projects.

.It should be, noted that the tensionyoi the spring 25fc'an b'e adjustedover awide range of operation without, disassembling the sash balance,or'without even removing it from the window frame in which'it ismounted,'merely by I adjusting the'screw'20 through. the opening 4| inthefa'ce plate'34 of thejfram'e. From. Fig. 3

it will beseen that asthis screw is turned'either clockwise or 'counterclockwi'se,its worm 22 en; gagesthe'teeth-of the disk I1torrotat'ethe disk 1injone'directioi'i, or the other; 'Sinceone end ofthe spring 25 jengages'thefsplit sleeve ZTYcarri'ed by thejdisk" n," thetension of'this spring may thus be adjustedat will;

4 From the' forego'ing it will be, seenthat the installed and readily"adj -uste d},

, "What I 'claimis';

' 1.I In'a "device of the class described, af sheet metal'hood providedwith an integral struck; up

hub, a diskprovided with an offset central portion :and, with gearteethinitsedgefsaid disk being rotatable on'saidhub, asleeve secured to andprojecting from the center of said disk, an

men? Wa el e t mo nte On S o to engage said teeth whereby said diskmaybe rotated,"a sheet metal spring :cuprhaving its. rim projecting towardtheoffset portion of said, disk, said cup being provided withastruck-up, aperaid-awe, and a tape having one end connected to said cup.and adapted to be wound around the rim of said cup.

2., In a device oithe class described, a sheet e eip o de v i ee i r .sewp hub, a disk provided with an offset central portion and with gearteeth in its edge, said disk 'being rotatable on said hub, a sleevesecured to and projecting from the center of said disk, an adjustableworm element mounted on said hood to engage said teeth wherebygsaid diskmay be rotated, a sheet metal spring cup having its rim projectingtoward the ofiset portion of said disk,

and having a second portion connected to said sleeve whereby said springmay be wound around said sleeve, a tape having one end connected to saidcup and adapted to be wound around the rim of said cup, a frame for saidhood provided with a tace plate having two openings therein, through oneof which the other end of said tape projects, said worm element havingan end accessible thru the other opening in said face plate whereby saidelement is adjustable while saiddevice is mounted in a window frame.

3 In a device of the class described, a sheet metal hood comprising aside member having a cut out portion at its upper corner, said sidemember being provided with an integral struck up hub infspaced relationto said cut-out por; tion, a. disk provided with an offset centralportion and with gear teeth inits. edge, said disk being rotatable onsaid hub, a sleeve secured to and: projecting from the center of saiddisk, an adjustable, worm element mountedon said hood with saidwormengaging said teeth whereby said-disk may be rotated and with a portionofsaid'worm projecting through saidcutout portion of said hood, a sheetmetal spring cup havingits rim projecting into the ofiset portion ofsaid disk, saidv cup being provided with a struck up, aperturedhubformed centrally thereonto engage-the. free;end'of said sleeve,.aretractile spring said .cup having one portion connected thereto andhaving a second portion n t aid lee q h by dsp i e m be; wound aroundsaid sleeve, a time having one end connected to said cup and adapted tobe woundaround the; rirnoI said cup,,.a frame for said hoodprovidedwitha faceplate having-two openings therein, through one-ofwhichrthe other n o said; tape, p jec s. ,saidw m elemen having an end,acoessible;-thru the other opening in said faceplate'wherebysaid,elementis adjustable while said, device is mounted ina V gear teeth inits edge a sleeve secured-to and i et n wmze he nte ofs id :disk about th ert r he e n l adj s able w0rm;,e1emen? mmmted naid-ai ed. t esew a teeth whereby said disk may be rotated,a; sheetmetal spring cup 3 having 7 its ri m projecting toward the fis p t onipd isk, vsa d,, upab s ln p vided with a struck upaperturedghub formedcentrally thereon to engage the free end; oisaid sleeve aretractilespringinsaid oup havingone portion connected, thereto andhaving asecond portion connecteddo said sleevewhereby said spring vb wund o nd said s eeve, eans p s g thrqu the n ur sinesaid hoodlsaid diskand said cup for, retaining the, .same, in operative re lati on;,-, anda tape havinggone end connected to said cup and adapted to be woundaround the rim of said cup.

5. In a device of the class described, a hood comprising a side memberhaving a cutout portion at its upper corner and provided with acentrally located aperture therein, a disk having a centrally locatedaperture therein and provided with gear teeth in its edge, a sleevesecured to and projecting from the center of said disk at the aperturetherein, an adjustable worm element on said hood with its worm engagingsaid teeth whereby said disk may be rotated, a portion of said wormprojecting through the cut-out portion of said hood, means for fasteningsaid worm element on said hood, a spring cup having its rim projectingtoward said disk, said cup being provided with a centrally locatedaperture therein, a retractile spring in said cup having one portionconnected thereto and having a second portion connected to said sleevewhereby said spring may be wound around said sleeve, means passingthrough the apertures in said hood, said disk and said cup for retainingthe same in operative position, and a tape having one end connected tosaid cup and adapted to be wound within around the rim of said cup.

6. In a device of the class described, a hood comprising a side memberhaving a cutout portion at its upper corner and provided with acentrally located aperture therein, a disk having a centrally locatedaperture therein and provided with gear teeth in its edge, a sleevesecured to and projecting from the center of said disk at the aperturetherein, an adjustable worm element on said hood with its worm engagingsaid teeth whereby said disk may be rotated, a portion of said wormprojecting through the cutout portion of said hood, and a piece struckup from said hood for fastening said worm thereto, a spring cup havingits rim projecting toward said disk, said cup being provided with acentrally located aperture therein, a retractile spring in said cuphaving one portion connected thereto and having a second portionconnected to said sleeve whereby said spring may be wound around saidsleeve, means passing through the apertures in said hood, said disk andsaid cup for retaining the same in operative position, and a tape havingone end connected to said cup and adapted to be wound Within around therim of said cup.

DONALD M. LEWIS. EDGAR L. GARDNER.

